In neurological and other medical examinations, it is often necessary to locate and outline areas of analgesia, or no-pain sensitivity, as well as areas of hypesthesia, or reduced pain sensitivity, of the skin of a patient. Such mapping procedures are necessary in cases of special examinations for the purpose of treatment of neurological disorders as well as in general medical checkups, in diagnosing other diseases, and in the testing the effects of local anesthesia.
Such mapping procedures can be performed by lightly striking the skin of a patient with a pin, while the patient reports on the degree of pain felt. If areas of no-pain sensitivity or of reduced sensitivity are located, more strikes with the pin are made in the general vicinity in order to determine the boundary of the affected area and to outline or map the same.
It can be appreciated that the closer such pin strikes are made, the more precise is the location of the affected areas. In addition, the more uniform the force of the pin strikes, the more reliable are the results.
If such a mapping procedure is conducted on large areas of the skin or over the entire body of a patient, the number of the required pin strikes may be exceedingly large and the overall procedure may take an exceedingly long time.
While examination of large relatively flat portions of the body may be facilitated by the use of an instrument in the form of a pin brush, the use of single pins is still required over many body areas, and a full examination can take several days.
It has also been found that muscular coordination of the medical examiner required to make pin strikes with the requisite uniformity is exceedingly difficult to attain except for persons at the height of their muscular coordination, and is often unattainable for an older practitioner. Therefore, in many cases, the differences in the pain sensitivity reported by the patient may be due not to the causes determined by the health condition of the patient, but by the variance in the intensity of the pin strikes made by the medical examiner. Thus, in some cases the variance in pain felt by the patient may be the test not of pain sensitivity of the skin but, in effect, of the muscular coordination of the medical examiner. Results of such tests are obviously unreliable for the purposes of medical diagnosis and treatment.
In order to overcome the disadvantages associated with pin striking procedures, a device which includes a rotatable wheel with sharp prongs mounted on the periphery of the wheel has been developed and widely accepted. The pin wheel which is rotatably mounted on a handle is conveniently rolled over the skin of a patient during a mapping procedure.
U.S. Pat. No 3,344,781 to Allen discloses a multi-purpose neurological diagnostic instrument which includes a pin wheel "C" in addition to other diagnostic devices.
U.S. Pat. No. 3,074,395 to Kevorkian discloses an algesimeter which includes a pin wheel 23 that is connected to a yielding mechanism. The yielding mechanism regulates the force applied to the pin wheel.
German patent No. 2,319,591 discloses a surgical needle roller which is releasable mounted in a holder for quick sterilizing. As illustrated in FIG. 4, a roller is secured at opposite ends to holder 1 by biasing springs.
German patent No. 3,245,286 discloses a skin and muscle massage treatment apparatus which includes two exchangeable rollers with rigid projections that are located in frame 1.
Currently, pin wheel algesimeters are designed to be reusable and thus, may be sterilized for each use. German patent No. 2,319,591 is an example of a algesimeter design which is particularly designed for sterilization of the roller.
With the present concern for diseases such as AIDS which are spread by blood-contaminated articles, there is considerable anxiety associated with devices that are intended to prick or puncture a subject's skin when used.
The present invention provides an algesimeter which has a disposable pin wheel that can be easily attachable/detachable to a handle structure.